The concentration of soil Olsen-P is rapidly increasing in many parts of China, where P budget(P input minus P output) is the main factor influencing soil Olsen-P. Understanding the relationship between soil Olsen-P a...The concentration of soil Olsen-P is rapidly increasing in many parts of China, where P budget(P input minus P output) is the main factor influencing soil Olsen-P. Understanding the relationship between soil Olsen-P and P budget is useful in estimating soil Olsen-P content and conducting P management strategies. To address this, a long-term experiment(1991–2011) was performed on a fluvo-aquic soil in Beijing, China, where seven fertilization treatments were used to study the response of soil Olsen-P to P budget. The results showed that the relationship between the decrease in soil Olsen-P and P deficit could be simulated by a simple linear model. In treatments without P fertilization(CK, N, and NK), soil Olsen-P decreased by 2.4, 1.9, and 1.4 mg kg^(–1) for every 100 kg ha^(–1) of P deficit, respectively. Under conditions of P addition, the relationship between the increase in soil Olsen-P and P surplus could be divided into two stages. When P surplus was lower than the range of 729–884 kg ha^(–1), soil Olsen-P fluctuated over the course of the experimental period with chemical fertilizers(NP and NPK), and increased by 5.0 and 2.0 mg kg^(–1), respectively, when treated with chemical fertilizers combined with manure(NPKM and 1.5 NPKM) for every 100 kg ha^(–1) of P surplus. When P surplus was higher than the range of 729–884 kg ha^(–1), soil Olsen-P increased by 49.0 and 37.0 mg kg^(–1) in NPKM and 1.5 NPKM treatments, respectively, for every 100 kg ha^(–1) P surplus. The relationship between the increase in soil Olsen-P and P surplus could be simulated by two-segment linear models. The cumulative P budget at the turning point was defined as the "storage threshold" of a fluvo-aquic soil in Beijing, and the storage thresholds under NPKM and 1.5 NPKM were 729 and 884 kg ha^(–1)P for more adsorption sites. According to the critical soil P values(CPVs) and the relationship between soil Olsen-P and P budget, the quantity of P fertilizers for winter wheat could be increased and that of summer maize could be decreased based on the results of treatments in chemical fertilization. Additionally, when chemical fertilizers are combined with manures(NPKM and 1.5 NPKM), it could take approximately 9–11 years for soil Olsen-P to decrease to the critical soil P values of crops grown in the absence of P fertilizer.展开更多
The improvement of soil productivity depends on a rational input of water and nutrients, optimal field management, and the increase of basic soil productivity（BSP）. In this study, BSP is defined as the productive ca...The improvement of soil productivity depends on a rational input of water and nutrients, optimal field management, and the increase of basic soil productivity（BSP）. In this study, BSP is defined as the productive capacity of a farmland soil with its own physical and chemical properties for a specific crop season under local field management. Based on 19-yr data of the long-term agronomic experiments（1989–2008） on a fluvo-aquic soil in Zhengzhou, Henan Province, China, the decision support system for agrotechnology transfer（DSSAT ver. 4.0） crop growth model was used to simulate yields by BSP of winter wheat（Triticum aestivium L.） and summer maize（Zea mays L.） to examine the relationship between BSP and soil organic carbon（SOC） under long-term fertilization. Five treatments were included：（1） no fertilization（control）,（2） nitrogen, phosphorus and potassium fertilizers（NPK）,（3） NPK plus manure（NPKM）,（4） 1.5 times of NPKM（1.5NPKM）, and（5） NPK plus straw（NPKS）. After 19 yr of treatments, the SOC stock increased 16.7, 44.2, 69.9, and 25.2% under the NPK, NPKM, 1.5NPKM, and NPKS, respectively, compared to the initial value. Among various nutrient factors affecting contribution percentage of BSP to winter wheat and summer maize, SOC was a major affecting factor for BSP in the fluvo-aquic soil. There were significant positive correlations between SOC stock and yields by BSP of winter wheat and summer maize（P〈0.01）, and yields by BSP of winter wheat and summer maize increased 154 and 132 kg ha^（–1） when SOC stock increased 1 t C ha^（–1）. Thus, increased SOC accumulation is a crucial way for increasing BSP in fluvo-aquic soil. The manure or straw combined application with chemical fertilizers significantly enhanced BSP compared to the application of chemical fertilizers alone.展开更多
The K+ adsorption kinetics of fluvo-aquic soil and cinnamon soil under different temperatureswere studied. The results showed: 1) The first order equations were the most suitable forfitting the adsorption under variou...The K+ adsorption kinetics of fluvo-aquic soil and cinnamon soil under different temperatureswere studied. The results showed: 1) The first order equations were the most suitable forfitting the adsorption under various temperature levels with constant K+ concentration indisplacing fluid. With temperature increasing, the fitness of Elovich equation increased,while those of power equation and parabolic diffusion equation decreased; 2)the apparentadsorption rate constant ka and the product of ka multiplied by the apparent equilibriumadsorption qincreased when temperature increased, while the apparent equilibrium adsorptionqreduced; 3)temperature influenced hardly the reaction order, the order of concentrationand adsorpton site were always 1 under various temperatures, if they were taken intoaccount simultaneously, the adsorption should be a two-order reaction process; 4)theGibbs free energy change △G of potassium adsorption were negative, ranged from -4444.56to -2450.63Jmol-1,and increased with temperature increasing, while enthalpy change △H,entropy change △S, apparent adsorption activation Ea, adsorption activation energy E1and desorption activation energy E2 were temperature-independent; 5)the adsorption wasspontaneous process with heat releasing and entropy dropping, fluvo-aquic soil releasedmore heat than cinnamon soil.展开更多
When the soil condition and depth to water table stay constant, climate condition will then be the only determinant of evaporation intensity of phreatic water from bare soil. Based on a series of long-term quality-con...When the soil condition and depth to water table stay constant, climate condition will then be the only determinant of evaporation intensity of phreatic water from bare soil. Based on a series of long-term quality-controlled data collected at the Wudaogou Hydrological Experiment Station in the Huaibei Plain, Anhui, China, the variation trends of the evaporation rate of phreatic water from bare soil were studied through the Mann-Kendall trend test and the linear regression trend test, followed by the study on the responses of evaporation to climate change. Results indicated that in the Huaibei Plain during 1991-2008, evaporation of phreatic water from bare soil tended to increase at a rate of 5% on monthly scale in March, June and July while in other months the increase was minor. On the seasonal basis, the evaporation saw significant increase in spring and summer. In addition, annual evaporation tended to grow evidently over time. When air temperature rises by 1 °C, the annual evaporation rate increases by 7.24–14.21%, while when the vapor pressure deficit rises by 10%, it changes from-0.09 to 5.40%. The study also provides references for further understanding of the trends and responses of regional evapotranspiration to climate change.展开更多
A systematic study concerning the effects of a long-term stationary fertilization on content and property of soil humus in fluvo-aquic soil sampled from Malan Farm, Xinji City, Hebei, and arid red soil and paddy red s...A systematic study concerning the effects of a long-term stationary fertilization on content and property of soil humus in fluvo-aquic soil sampled from Malan Farm, Xinji City, Hebei, and arid red soil and paddy red soil sampled from the Institute of Red Soil, Jinxian County, Jiangxi was conducted. The results showed that long-term fertilization had effects not only on the content and composition of soil humus, but also on the physico-chemical property of humus. With applying organic manure or combined application of organic manure and chemical fertilizer, E4 and E6 values of humic acid decreased in fluvo-aquic soil and arid red soil, but increased in paddy red soil. In paddy red soil, E4 and E6 values of humic acid increased also with a single application of chemical fertilizer, but E4 and E6 values had less change of humic acid in fluvo-aquic soil and arid red soil. The effects on the visible spectroscopic property of f ulvic acid were different from that of humic acid. Long-term application of organic manure or combined application of organic manure and chemical fertilizer could increase E4 and E6 values of f ulvic acid in three types of soil. Single application of chemical fertilizer had less effect on the E4 and E6. Long-term fertilization could also influence the ultraviolet spectroscopic property of humus. With a single application of organic manure or combined application of organic manure and chemical fertilizer, the ultraviolet absorbance of humic acid and f ulvic acid increased in the three types of soil. But this effect was obvious only in short wave length, and the effect could decrease if the wave length increased. With a single application of chemical fertilizer the ultraviolet absorbance of fulvic acid could increase, but it of humic acid increased only in fluvo-aquic soil. Long-term application of organic manure or combined application of organic manure and chemical fertilizer could increase the content of total acidic groups, carboxy groups and phenolic hydroxy groups of humic acid and fuvic acid in the three types of soil. Single application of chemical fertilizer had less effect on the content of total acidic groups, carboxy groups and phenolic hydroxy groups of humic acid and fuvic acid in the three types of soil.展开更多
基金supported by the National Natural Science Foundation of China (41471249)the Special Scientific Research Fund of Agricultural Public Welfare Profession of China (201503120)
文摘The concentration of soil Olsen-P is rapidly increasing in many parts of China, where P budget(P input minus P output) is the main factor influencing soil Olsen-P. Understanding the relationship between soil Olsen-P and P budget is useful in estimating soil Olsen-P content and conducting P management strategies. To address this, a long-term experiment(1991–2011) was performed on a fluvo-aquic soil in Beijing, China, where seven fertilization treatments were used to study the response of soil Olsen-P to P budget. The results showed that the relationship between the decrease in soil Olsen-P and P deficit could be simulated by a simple linear model. In treatments without P fertilization(CK, N, and NK), soil Olsen-P decreased by 2.4, 1.9, and 1.4 mg kg^(–1) for every 100 kg ha^(–1) of P deficit, respectively. Under conditions of P addition, the relationship between the increase in soil Olsen-P and P surplus could be divided into two stages. When P surplus was lower than the range of 729–884 kg ha^(–1), soil Olsen-P fluctuated over the course of the experimental period with chemical fertilizers(NP and NPK), and increased by 5.0 and 2.0 mg kg^(–1), respectively, when treated with chemical fertilizers combined with manure(NPKM and 1.5 NPKM) for every 100 kg ha^(–1) of P surplus. When P surplus was higher than the range of 729–884 kg ha^(–1), soil Olsen-P increased by 49.0 and 37.0 mg kg^(–1) in NPKM and 1.5 NPKM treatments, respectively, for every 100 kg ha^(–1) P surplus. The relationship between the increase in soil Olsen-P and P surplus could be simulated by two-segment linear models. The cumulative P budget at the turning point was defined as the "storage threshold" of a fluvo-aquic soil in Beijing, and the storage thresholds under NPKM and 1.5 NPKM were 729 and 884 kg ha^(–1)P for more adsorption sites. According to the critical soil P values(CPVs) and the relationship between soil Olsen-P and P budget, the quantity of P fertilizers for winter wheat could be increased and that of summer maize could be decreased based on the results of treatments in chemical fertilization. Additionally, when chemical fertilizers are combined with manures(NPKM and 1.5 NPKM), it could take approximately 9–11 years for soil Olsen-P to decrease to the critical soil P values of crops grown in the absence of P fertilizer.
基金supported by the National Basic Research Program of China(973 Program,2011CB100501)the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2015BAD22B03)+1 种基金the National High-Tech R&D Program of China(2013AA102901)the Special Fund for Agro-scientific Research in the Public Interest,China(201203077)
文摘The improvement of soil productivity depends on a rational input of water and nutrients, optimal field management, and the increase of basic soil productivity（BSP）. In this study, BSP is defined as the productive capacity of a farmland soil with its own physical and chemical properties for a specific crop season under local field management. Based on 19-yr data of the long-term agronomic experiments（1989–2008） on a fluvo-aquic soil in Zhengzhou, Henan Province, China, the decision support system for agrotechnology transfer（DSSAT ver. 4.0） crop growth model was used to simulate yields by BSP of winter wheat（Triticum aestivium L.） and summer maize（Zea mays L.） to examine the relationship between BSP and soil organic carbon（SOC） under long-term fertilization. Five treatments were included：（1） no fertilization（control）,（2） nitrogen, phosphorus and potassium fertilizers（NPK）,（3） NPK plus manure（NPKM）,（4） 1.5 times of NPKM（1.5NPKM）, and（5） NPK plus straw（NPKS）. After 19 yr of treatments, the SOC stock increased 16.7, 44.2, 69.9, and 25.2% under the NPK, NPKM, 1.5NPKM, and NPKS, respectively, compared to the initial value. Among various nutrient factors affecting contribution percentage of BSP to winter wheat and summer maize, SOC was a major affecting factor for BSP in the fluvo-aquic soil. There were significant positive correlations between SOC stock and yields by BSP of winter wheat and summer maize（P〈0.01）, and yields by BSP of winter wheat and summer maize increased 154 and 132 kg ha^（–1） when SOC stock increased 1 t C ha^（–1）. Thus, increased SOC accumulation is a crucial way for increasing BSP in fluvo-aquic soil. The manure or straw combined application with chemical fertilizers significantly enhanced BSP compared to the application of chemical fertilizers alone.
基金supported by the National Science Foundation of China(49391600)the Society Commonweal Fund(2001DIA20024).
文摘The K+ adsorption kinetics of fluvo-aquic soil and cinnamon soil under different temperatureswere studied. The results showed: 1) The first order equations were the most suitable forfitting the adsorption under various temperature levels with constant K+ concentration indisplacing fluid. With temperature increasing, the fitness of Elovich equation increased,while those of power equation and parabolic diffusion equation decreased; 2)the apparentadsorption rate constant ka and the product of ka multiplied by the apparent equilibriumadsorption qincreased when temperature increased, while the apparent equilibrium adsorptionqreduced; 3)temperature influenced hardly the reaction order, the order of concentrationand adsorpton site were always 1 under various temperatures, if they were taken intoaccount simultaneously, the adsorption should be a two-order reaction process; 4)theGibbs free energy change △G of potassium adsorption were negative, ranged from -4444.56to -2450.63Jmol-1,and increased with temperature increasing, while enthalpy change △H,entropy change △S, apparent adsorption activation Ea, adsorption activation energy E1and desorption activation energy E2 were temperature-independent; 5)the adsorption wasspontaneous process with heat releasing and entropy dropping, fluvo-aquic soil releasedmore heat than cinnamon soil.
基金financially supported by“the Fundamental Research Funds for the Central Universities”of Hefei University of Technology(No.JZ2014HGBZ0040)the National Natural Science Foundation of China(No.51509064+2 种基金No.51309071No.51309155)the National Key Research and Development Programs of China(Grand 2016YFA0601601,2016YFA0601501)
文摘When the soil condition and depth to water table stay constant, climate condition will then be the only determinant of evaporation intensity of phreatic water from bare soil. Based on a series of long-term quality-controlled data collected at the Wudaogou Hydrological Experiment Station in the Huaibei Plain, Anhui, China, the variation trends of the evaporation rate of phreatic water from bare soil were studied through the Mann-Kendall trend test and the linear regression trend test, followed by the study on the responses of evaporation to climate change. Results indicated that in the Huaibei Plain during 1991-2008, evaporation of phreatic water from bare soil tended to increase at a rate of 5% on monthly scale in March, June and July while in other months the increase was minor. On the seasonal basis, the evaporation saw significant increase in spring and summer. In addition, annual evaporation tended to grow evidently over time. When air temperature rises by 1 °C, the annual evaporation rate increases by 7.24–14.21%, while when the vapor pressure deficit rises by 10%, it changes from-0.09 to 5.40%. The study also provides references for further understanding of the trends and responses of regional evapotranspiration to climate change.
文摘A systematic study concerning the effects of a long-term stationary fertilization on content and property of soil humus in fluvo-aquic soil sampled from Malan Farm, Xinji City, Hebei, and arid red soil and paddy red soil sampled from the Institute of Red Soil, Jinxian County, Jiangxi was conducted. The results showed that long-term fertilization had effects not only on the content and composition of soil humus, but also on the physico-chemical property of humus. With applying organic manure or combined application of organic manure and chemical fertilizer, E4 and E6 values of humic acid decreased in fluvo-aquic soil and arid red soil, but increased in paddy red soil. In paddy red soil, E4 and E6 values of humic acid increased also with a single application of chemical fertilizer, but E4 and E6 values had less change of humic acid in fluvo-aquic soil and arid red soil. The effects on the visible spectroscopic property of f ulvic acid were different from that of humic acid. Long-term application of organic manure or combined application of organic manure and chemical fertilizer could increase E4 and E6 values of f ulvic acid in three types of soil. Single application of chemical fertilizer had less effect on the E4 and E6. Long-term fertilization could also influence the ultraviolet spectroscopic property of humus. With a single application of organic manure or combined application of organic manure and chemical fertilizer, the ultraviolet absorbance of humic acid and f ulvic acid increased in the three types of soil. But this effect was obvious only in short wave length, and the effect could decrease if the wave length increased. With a single application of chemical fertilizer the ultraviolet absorbance of fulvic acid could increase, but it of humic acid increased only in fluvo-aquic soil. Long-term application of organic manure or combined application of organic manure and chemical fertilizer could increase the content of total acidic groups, carboxy groups and phenolic hydroxy groups of humic acid and fuvic acid in the three types of soil. Single application of chemical fertilizer had less effect on the content of total acidic groups, carboxy groups and phenolic hydroxy groups of humic acid and fuvic acid in the three types of soil.
